NYC Health Department Uses Yelp to Track Foodborne Illness

Below:

Next story in Science

Using customer reviews of New York City restaurants on the online
service Yelp, health investigators were able to identify
outbreaks of foodborne illness that hadn't been reported to the
health department.

The New York City Department of Health and Mental Hygiene worked
with Columbia University and Yelp on a pilot project to explore
the potential for using Yelp to identify unreported outbreaks,
according to their report.

The researchers mined through about 294,000 restaurant reviews
posted on Yelp over nine months during 2012 and 2013. To find the
reviews likely of describing foodborne
illness, the researchers looked for posts containing the
keywords "sick," "vomit," "diarrhea" or "food poisoning."

The results showed that nearly 500 people had described an
episode of symptoms consistent with foodborne illness. Only 3
percent of these incidents had been reported to New York City's
nonemergency 311 services. [ Top
7 Germs in Food that Make You Sick ]

The researchers considered only incidents where two or more
people who had eaten at the same restaurant reported feeling ill,
and found about 130 of the reviews required further
investigation. Telephone interviews with 27 reviewers who
responded to the researchers' requests revealed three previously
unreported restaurant-related outbreaks, according to the study,
published today (May 22) in the Centers for Disease Control and
Prevention's Morbidity and Mortality Weekly Report.

In the outbreaks reported at each of the three restaurants, three
to seven people became sick after consuming a meal. The
researchers found that the patrons likely had gotten sick after
eating the house salad, shrimp and lobster cannelloni, and
macaroni and cheese spring rolls.

The researchers investigated two of the three restaurants after
the interviews and found multiple code violations, including
serving unwashed vegetables and improper food storage conditions.
In one of the restaurants, investigators found a mouse and live
roaches.

The findings suggest that Yelp may be the latest among websites
and social media platforms, such as
Google Flu Trends and Twitter, that researchers and
health authorities can use to track disease outbreaks. For
foodborne illnesses, a restaurant-patron-review-based system like
Yelp can identify outbreaks that are too small to be detected by
larger surveillance systems, the researchers said.

Yelp also offers researchers a way to communicate with reviewers
and confirm the reports. To follow up with reviewers, the
researchers created a Yelp account to send private messages to
reviewers' Yelp accounts, requesting phone interviews.

For the 290 reviews that mentioned symptoms but didn't require
further investigation, the researchers sent messages advising
reviewers of the availability of 311 reporting. The majority of
the 32 reviewers who responded to these messages said they were
unaware of the 311 system.

The 311 service receives about 3,000
food poisoning complaints each year, 1 percent of which
would later be identified as outbreak-related, the researchers
said.

The New York City Department of Health and Mental Hygiene plans
to continue this project and expand it to include additional
review websites. Yelp will provide daily, rather than weekly,
review feeds to researchers so that they can investigate
potential foodborne illness outbreaks faster, the researchers
said.